The First Unitarian Society of Madison (FUS) is a Unitarian Universalist congregation in Shorewood Hills, Wisconsin. Its meeting house was designed by Frank Lloyd Wright and built by Marshall Erdman in 1949–1951, and has been designated a U.S. National Historic Landmark for its architecture. With over 1,000 members, it is one of the ten largest Unitarian Universalist congregations in the United States.

The First Unitarian Society of Madison is part of the Unitarian Universalist Association and affirms the Seven Principles and Six Sources. The Society also adheres to the Continuing Bond of Union established at their founding in 1879 and reaffirmed in 1980:

"We whose names are hereunto inscribed, desiring a religious organization in the spirit of Jesus of Nazareth, which shall make integrity of life its first aim and leave thought free, associate ourselves together as the First Unitarian Society of Madison and accept to its membership those of whatever theological opinion who wish to unite with us in the promotion of truth, righteousness, reverence, and charity among all. As part of a non-creedal tradition, the First Unitarian Society of Madison welcomes all regardless of creed, religion, sexual orientation, gender identity, race, ethnicity, and ability."

The First Unitarian Society of Madison was established in 1879 shortly after the 1878 Session of the Wisconsin Conference of Unitarian & Independent Churches led to a resurgence of the Unitarians in Madison. Influenced greatly by the Reverend Jenkin Lloyd Jones, a prominent Unitarian minister (and Frank Lloyd Wright's uncle), the early members held that an ethical rather than theological agreement was the hallmark of Unitarianism.

The Reverend Henry M. Simmons was called as the Society's first settled minister shortly after its founding, but departed within two years. Shortly after his departure, the Reverend Joseph Henry Crooker took over as the called minister and led the congregation in establishing their first building in 1885 which was designed by Peabody and Stearns of Boston. During Crooker's tenure, the congregation experienced significant growth in their Sunday School program, in addition to establishing the Women's Alliance, the Channing Club (a university student group), the Lend-A-Hand Club, and the Contemporary Club (a current topics discussion group).

By 1910 there were 105 pledging units on the roster (a pledging unit can be an individual donor or a family donor), but by 1940 only 48 pledging units were recorded with the decline attributed to dissent among members. In 1941, the Reverend Kenneth Patton was called to serve as minister and the Society's membership nearly doubled in a few years.

In 1945, the Society elected to sell their original buildings after receiving a substantial offer for the property originally located in downtown Madison. The following year, after much debate, the Society commissioned Frank Lloyd Wright to design the new Meeting House. Four acres of land in Shorewood Hills, surrounded by few structures and overlooking the University of Wisconsin agricultural fields, was purchased as the new site. The new building opened in 1951. Today, the University of Wisconsin hospital and a busy University Avenue surround the Meeting House.

The Reverend Max D. Gaebler served as the settled minister for 35 years. In 1988, the Reverend Michael A. Schuler was called as the settled minister and retired in 2018 after 30 years of dedicated service. Under the leadership and tenures of both the Reverend Gaebler and Schuler, the Society experienced significant growth and presently registers over 1,500 Members and Affiliates. In 2008, a gold-level LEED Certified Atrium addition was built on the campus to accommodate the increase in membership.